Roberto Hernandez is doing something new

After a disappointing series loss in Toronto, the Rays are coming home to host the Yankees, and Roberto Hernandez will get the start in game one tomorrow. I think that getting lost in his 5.24 ERA and the overall disappointing start to the season for Rays' pitching is the fact that Hernandez has been good. Like, not just "keeping a spot warm for Chris Archer, Alex Torres, or Jake Odorizzi good." More like "keeping Archer, Torres, and Odorizzi in Durham good." SIERA, my ERA estimator of choice, believes that out of starters to have pitched at least 40 innings, Roberto Hernandez has been the 21st best in the Major Leagues this year.

Hernandez is striking out 21.2% of the batters he faces and walking 6.6%, while having over 50% of the balls put in play against him be ground balls. Yes, his HR/FB is a freakishly high 25%, which means every batter has hit against him with the power of Adam Dunn or Michael Morse, but that's unlikely to continue. The same skills that enable a pitcher to strike out a fifth of the batters he faces also enable him to post a reasonable HR/FB rate over the long run.

Now, I've already talked about one of the ways Jim Hickey and the Rays staff have improved Roberto Hernandez—by throwing more of his excellent changeups—but there was something else new in his approach that I had missed until now. Against left-handed batters, Hernandez has been throwing a front-door sinker. This means that he aims his two-seam fastball at the batter's hip, and then lets it's excellent horizontal movement carry the pitch back over the plate or nearly so. He's gotten plenty of called strikes and plenty of whiffs with the pitch. It looks really effective, and I just assumed it's something he's always thrown. I was wrong.

Here, from the Baseball Prospectus and Brooks Baseball player cards, is the location distribution of Roberto Hernandez's sinkers to lefties over his entire career:

And here it is in 2013:

Yes, Hernandez is always going to pound the down and outside corner of the zone, because that's how one gets ground balls, but he used to be a one trick pony against lefties. Now he's coming inside with the pitch as well. Over his whole career, he's thrown a sinker on the inner third or off the plate inside only 19.5% of the time. In 2013, 38.3% of the time.

The change in approach has been borne out in the results. Over his career, Hernandez has only struck out 11.4% of the left-handed batters he's faced. In 2013, 20.2%. As I so often find myself doing, I can only tip my cap to Jim Hickey and whoever else works with the Rays pitching staff. They once again have taken a talented but flawed and predictable pitcher and have gotten him to play to his strengths while at the same time becoming less predictable.

A side note about perception. When I started writing this article, I was certain that the entire Rays staff was throwing front-door sinkers more often this year. That's not true at all. Alex Cobb and Jeremy Hellickson are actually throwing that pitch less often. All that had happened is I had become more aware of the pitch by watching Hernandez, and had started taking greater note of it whenever anyone threw one. Another reminder of why it's a good idea to check the data whenever you think you see a pattern.